Vapor generator carburetion system

ABSTRACT

A housing having an air inlet and an exhaust is divided into a central plenum and a combustion chamber by a porous member. A rotatable shaft passing through the plenum is driven by a motor, and drives a fuel pump, a blower and an atomizer/vaporizer. Fuel is pumped to the atomizer/vaporizer where it is forced outwardly by the rotation through porous walls into a scroll where it is mixed with the air introduced by the blower. The scroll converts the velocity of the mixture into a pressure head so that upon entering the plenum it passes through the porous member. It burns on the surface of the porous member in the combustion chamber, heating and vaporizing fluid carried in a tube in the combustion chamber.

United States Patent Laessig 5] Dec. 16, 1975 VAPOR GENERATOR CARBURETION 3,563,212 2/1971 Hoagland 122/367 SYSTEM 3,672,839 6/1972 Moore 122/367 x [75] Inventor: Rudolf R. Laessig, West Chester,

[73] Assignee: General Electric Company,

Fairfield, Conn.

[22] Filed: June 3, 1974 [21] Appl. No.: 475,647

[52] US. Cl 122/250 R; 122/367 R; 431/168; 122/248 [51] Int. Cl. F22B 27/08 [58] Field of Search 122/250, 367 R, 367 PF, 122/248; 431/168, 169

[56] References Cited UNITED STATES PATENTS 2,491,517 12/1949 Powers et a1. 431/169 X 2,620,864 12/1952 Ray v 1 431/168 3,029,863 4/1962 Downs 431/169 3,336,910 8/1967 Taylor 122/250 Primary Examiner-Kenneth W. Sprague Attorney, Agent, or FirmRaymond H. Quist; Allen E. Amgott [5 7 ABSTRACT A housing having an air inlet and an exhaust is divided into a central plenum and a combustion chamber by a porous member. A rotatable shaft passing through the plenum is driven by a motor, and drives a fuel pump, a blower and an atomizer/vaporizer. Fuel is pumped to the atomizer/vaporizer where it is forced outwardly by the rotation through porous walls into a scroll where it is mixed with the air introduced by the blower. The scroll converts the velocity of the mixture into a pres sure head so that upon entering the plenum it passes through the porous member. It burns on the surface of the porous member in the combustion chamber, heating and vaporizing fluid carried in a tube in the Combustion chamber.

5 Claims, 5 Drawing Figures US. Patent Dec.16,1975 SheetlofZ 3,926,150

US. Patent Dec. 16, 1975 Sheet20f2 3,926,150

VAPOR GENERATOR CARBURETION sYsraM BACKGROUND OF THE'INVENTIONFW This invention relates generally toivapor generators and more particularly to an improved carburetion system for a vapor generator having lowpollutant emission characteristics and highefficiency. g

As widely publicized, one drawback of contemporary piston type internal combustion engines is the excessive amounts of air pollutants which result from their operation. Although efforts are being made to reduce the pollutants emitted by these engines, alternate power generating means are also being explored. One such alternate is the external combustion engine. In such an engine, a fuel (generally liquid) is burned in a combustor and the resulting hot gases are used to vaporize a liquid which in turn drives a prime mover such as an expander, turbine, etc.

External combustion generally results in more complete consumption of the hydrocarbons than the intermittent combustion in an internal combustion, piston type engine. Excessive production of nitrogen oxides and carbon monoxides still remain a problem, particu larly in units small enough to be mobile. The rate of nitrogen oxides formation decreases rapidly as the temperature of the reaction gases is reduced (see for example U.S. Pat. No. 3,675,629).

When a liquid fuel is burned in a vapor generator, improved combustion occurs if the fuel is vaporized or atomized to very fine drops and uniformly mixed with the combustion air. In addition, when the load the prime mover is driving is reduced, there should be a proportionate reduction of fuel consumed.

SUMMARY OF THE INVENTION In a preferred form, a cylindrical housing has a central air inlet, and an exhaust port in the cylindrical wall. A porous member divides the housing into a central plenum and an annular combustion chamber. A tube carrying a liquid to be vaporized is located in the combustion chamber. A shaft mounted for rotation carries a fuel pump, blower and atomizer/vaporizer for rotation with it. A scroll in said plenum contains the atomizer/vaporizer and blower. The fuel is pumped to the atomizer/vaporizer and is forced outwardly by the rotation. In the scroll the atomized/vaporized fuel is mixed with the air introduced by the blower. The scroll con verts the velocity of the mixture to a pressure head which forces the mixture through the porous member. The mixture burns on the surface of the porous member. In some versions a two stage blower scroll assembly is employed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic in cross-section of a vapor generator in accordance with the invention;

FIG. 2A is a plan view of the scroll;

FIG. 2B is a side view, in cross-section of the scroll;

FIG. 2C is the scroll cover; and

FIG. 3 is a cross-section of a laminar fluid resistance which may be employed in the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, the interior of container is divided by porous burner 12 into combustion chamber 14 and plenum l6. Passing through plenum 16 is a shaft 2 18 which is rotated at various desired speeds by. motor 20. Rotating with shaft 18 is fuel pump 22. Fuel pump 22 may be of thetype disclosed in U.S. Pat. No. 3,647,3 14. Fuel is admitted t pump 22 via line 24, and is pumped out through line 26.

Fuel is ejected from line 26 into atomizer/vaporizer 28. Atomizer/vaporizer 28 has one or more concentric cylindrical walls of porous material and rotates with shaft 18.. In passing through the walls the fuel is vaporized or broken into fine drops. The rings serve to distribute the fuel evenly about their circumference and release it in fine drops and vapor. Blower 30, which also rotates with shaft 18, draws in air through central opening 32, and blows it out through scroll 34 (better seen in FIG. 2.). Scroll 34 is shown in FIGS. 2A and 2B to include spiral walls 5 2 which, together with cover 54 in FIG. 2C, increases the pressure of the combustible mixture and directs it to second stage scroll 38 with its blower 36. Second stage scroll 38 further increases the pressure as well as providing additional mixing. From scroll 38 the mixture enters plenum 16 (FIG. 1). In some cases a single stage scroll may be adequate.

The fuel/air mixture enters plenum 16 through exit 40'. It passes through porous burner wall 12 and burns on the outer surface of this wall. Ignitor 42 is used to initiate combustion, and coil 44 carries the working fluid to be heated and vaporized. The products of combustion pass out exhaust 46.

In both pump 22 and blowers 30 and 36 the pressure increases in proportion to the square of the rotational speed. Thus the fuel/air ratio remains constant for all flow rates as long as the resistance characteristic of the burner, boiler and exhaust systems are the same as in the fuel system. Matching the resistance of the burner, boiler and exhaust can be performed by inserting a laminar resistance in fuel line. 26. Such a resistance increases linearly with the flow rate rather than as the square of the flow rate as with a turbulent resistance such as an orifice.

Although other types of laminar resistances may be used, a laminar resistance which has been found to be simple and easily adjustable is shown in FIG. 3. Inserted in fuel line 26 is tube 48, typically 4 to 6 inches long and having an inside diameter of 60 to mils in which is placed rod 50 so that a gap of 10 to 20'mils remains. Varying the diameter of rod 50 or its length changes the resistance to flow. Because of irregularities (bends, etc.) of the tube and rod, the rod is essentially centerized as shown.

It should be recognized that the vapor generator as shown in FIG. 1 is simplified so as not to obscure the invention. For example, container 10 would normally be enclosed to provide an air duct in which incoming air would be heated. Similarly, coil 44 may be preceded by a coil imbedded in wall 12 which would serve the dual purpose of heating the working fluid while cooling the wall. In addition, other changes and modifications can be made without departing from the spirit of the invention and the scope of the appended claims.

I claim:

1. In a vapor generator having a central plenum formed by a porous member for receiving a combustible mixture, an improved carburetion system comprismg:

a rotatable member having secured thereto for rotation with it: a liquid fuel pump, a blower, and

said scroll means in two stages with a blower in each stage.

3. A vapor generator comprising:

a housing having an air inlet and an exhaust;

a porous member dividing said housing into a central 7 plenum and a combustion chamber;

.a blower positioned to move air through said inlet;

a fuel pump;

a fuel atomizer/vaporizer;

means for conveying fuel from said fuel pump to said antomizer/vaporizer;

means for rotating said fuel pump and said blower at the same speeds;

means for mixing said atomized/vaporized fuel with said air to form a combustible mixture;

said means for mixing said atomized/vaporized fuel with said air includes scroll means which also converts the velocity of the mixture caused by said blower to a pressure head;

tubing means contained in said combustion chamber for carrying the fluid to be vaporized; and

means for igniting said combustible mixture.

4. A vapor generator according to claim 3 wherein:

said scroll means is in said plenum.

5. A vapor generator according to claim 4 wherein said blower is in said scroll means. 

1. In a vapor generator having a central plenum formed by a porous member for receiving a combustible mixture, an improved carburetion system comprising: a rotatable member having secured thereto for rotation with it: a liquid fuel pump, a blower, and a fuel atomizer/vaporizer; means for rotating said rotatable member; conveying means for delivering to said fuel atoMizer/vaporizer fuel pumped by said liquid fuel pump; said fuel atomizer/vaporizer directing atomized and/or vaporized fuel outwardly; said blower positioned to mix said atomized and/or vaporized fuel with air and blow the mixture into said plenum; and scroll means for converting the velocity of the mixture caused by said blower to a pressure head.
 2. A vapor generator according to claim 1 wherein: said scroll means in two stages with a blower in each stage.
 3. A vapor generator comprising: a housing having an air inlet and an exhaust; a porous member dividing said housing into a central plenum and a combustion chamber; a blower positioned to move air through said inlet; a fuel pump; a fuel atomizer/vaporizer; means for conveying fuel from said fuel pump to said antomizer/vaporizer; means for rotating said fuel pump and said blower at the same speeds; means for mixing said atomized/vaporized fuel with said air to form a combustible mixture; said means for mixing said atomized/vaporized fuel with said air includes scroll means which also converts the velocity of the mixture caused by said blower to a pressure head; tubing means contained in said combustion chamber for carrying the fluid to be vaporized; and means for igniting said combustible mixture.
 4. A vapor generator according to claim 3 wherein: said scroll means is in said plenum.
 5. A vapor generator according to claim 4 wherein said blower is in said scroll means. 